1. Field of the Invention
The present invention relates to organic bone void fillers comprising carbonaceous material for repairing bone voids, and particularly structural bone voids.
2. Description of Related Art
Bone is a regenerative tissue that can sometimes effectively repair fracture damage and small voids, but trauma that results in the loss of a large bone segment requires the use of a bone void filler to bridge the gap between bone segments. Bone void fillers are natural or synthetic materials placed into the bone defect to assist in bone regeneration and provide a three-dimensional structure to which bone tissue and cells can attach or be transplanted to regrow and repair damaged bone segments. Autologous, allogeneic, or xenogeneic bone grafts can be used for this purpose. However, in major traumatic injury, there is usually insufficient autologous bone available as a void filler. In addition, harvesting of the graft from the donor site for bone autografts causes a secondary trauma to the patient. This is avoided by the use of allografts and xenografts; however, these bone grafts require the use of immunosuppressives to avoid implant rejection by the patient, can transmit viruses, and have a relatively high failure rate.
Synthetic bone void fillers such as demineralized bone matrix or polymethylmethacrylate have also been employed. However, current bone fillers are generally intended for use only in voids that are not intrinsic to the stability of the bone structure, since most available materials possess insufficient strength and ultimate stress capabilities for such applications. Implants used for bone voids intrinsic to structural stability of the bone often involve permanent implant materials formed from metal, polymers, or composites; however, these types of implants are prone to corrosion and leaching. In addition, all metals, most ceramics, and many polymers are not bioresorbable, and cannot be replaced by the patient's own bone tissue. Thus, there remains a need in the art for a sufficiently strong temporary bone void filler suitable for use in load-bearing applications, that provides a template for osteogenesis that gradually degrades and is resorbed as it is replaced by bone tissue, until bone generation/regeneration is complete.